Latest compatible version of Classicube from the original GitHub repository (https://github.com/ClassiCube/ClassiCube) that can be compiled on Classicube for PowerMac PPC running Mac OS X 10.4.

misc/xbox360/ps_coloured.hlsl

@@ -0,0 +1,7 @@
+struct INPUT_VERTEX {
+   float4 col : COLOR0;
+};
+
+float4 main(INPUT_VERTEX input) : COLOR0 {
+	return input.col;
+}